Performance comparison of LMS and RLS channel estimation algorithms for 4G MIMO OFDM systems

Multiple input multiple output (MIMO) technology allows mobile networks to obtain higher signal to noise ratio to achieves considerable performance gain. It provides the significant performance improvement for the fourth generation (4G) communication systems. This paper, we compare the performance of least mean square (LMS) and recursive least square (RLS) channel estimation (CE) algorithm for MIMO orthogonal frequency division multiplexing (OFDM) systems. The simulation results show that the RLS has better mean square error (MSE) performance compared with LMS algorithm. The RLS CE algorithm has better anti-noise as well as tracking ability. But the RLS CE algorithm suffers from higher complexity than LMS CE algorithm. In addition, when the number of receiving antenna is greater than transmitting antenna then the performance is increase significantly in both algorithms and vice versa. Furthermore, as the SNR is increases from 5 to 15dB then MSE is deceases with each iteration. Therefore, the advantage in the MSE and convergence towards true channel coefficient may be significantly useful for future mobile communications which allow broadband multimedia Internet access and wireless connection anywhere, and any time.